Brand: Lenovo
Category: Mobile Phone
Document Type: Parts/Service
Language: EN
Parts/Service for P70
Uploaded: Nov. 21, 2025, 8:52 p.m.
Manual Publish Date: 2014-11-03
1. Appearance: Shows the external views of the mobile phone.
2. Layout of main board: Illustrates the components on the front and back of the main board.
3. Baseband: Presents a block diagram of the hardware system, detailing major components and their interconnections.
4. Main adverse analysis: Provides troubleshooting guides for various common issues such as LCD display problems, camera defects, ring/vibration issues, charging problems, keyboard malfunctions, calling issues, power-on failures, and radio frequency problems.
5. Disassembly Guide: Offers step-by-step instructions with accompanying images on how to take apart the mobile phone.
6. Assemble Guide: Instructs on how to reassemble the mobile phone, referring back to the disassembly process.
Troubleshooting and error codes
| Issue | Troubleshooting Steps |
|---|---|
| LCD DISPLAY - No display on screen after power-on | 1. Check LCD FPC connection. If good, reassemble and check phone. 2. If still no display, replace LCD. 3. Check EMI devices (Z1601-Z1605) for solder issues. 4. Check for cold solder joints around LCD and connector. |
| LCD backlight without lighting | 1. Check FPC connection. 2. Re-verify backlight after replacing LCD. 3. Check voltages across C1612. 4. Check welding of U1603 and peripheral devices. |
| CAMERA DEFECTS - Can not take photos | 1. Check camera module position and reassemble. 2. Replace camera module. 3. Check camera module connector welding. 4. Check EMI device (Z1701-Z1705). 5. Check if front camera is abnormal. 6. Check main chip U401 welding. |
| RING AND VIBRATION - No vibration | 1. Check for structural interference. 2. Replace motor and check surrounding circuit (R1808, C1811). 3. Replace U503 chip. |
| RING AND VIBRATION - No ring | 1. Replace Speaker and check SPK circuit. 2. Use earphone to test for audio signal. Check J1803 KB connector. 3. Check main chip U503. |
| CHARGING - No charging display after plugging the charger in | 1. Replace charger (J801). 2. Replace battery and measure voltage. 3. Check U630 module welding. 4. Replace U503. |
| CHARGING - Charging shown but not full charging | 1. Replace battery. 2. Check VCHG voltage and VCDT/ISENSE circuit components. 3. Replace U630 module device. 4. Replace U503. |
| KEYBOARD AND KEYBOARD BACKLIGHT - Abnormal operation of side keys | 1. Check keyboard FPC for cold solder joint/short circuit. 2. Replace side keys FPC if fractured. 3. Check circuit device of side keys and power key for cold solder joint/missing device. 4. Replace U401/U503. |
| KEYBOARD AND KEYBOARD BACKLIGHT - Abnormal operation of CTP keyboard | 1. Perform CTP test. If abnormal, replace CTP. 2. If issue persists, check CTP connector J1601 or main chip U401 welding. |
| CALLING - No voice heard from the other side during the call | 1. Use earphone/hands-free to check for voice. 2. Replace headphones. 3. Check B1403, B1404, C1428, C1427, D1403, D1404 welding. 4. Replace U503. |
| CALLING - No voice heard from your side during the call | 1. Check receiver and peripheral devices welding. 2. Check receiver module device welding and replace if necessary. 3. Check U503 and related components. |
| POWER-ON FAILURE | 1. Check power key FPC assembly. 2. Power on separate main board to check current. 3. Check 26MHz on X801. 4. Check X801 welding. 5. Check main power supply of U503. 6. Replace U503. |
| LCD on when close to the ear during the call; LCD off when away from the ear. | 1. Check P-Sensor related circuit or replace U1502. 2. Check touch screen pasting. 3. Check G-SENSOR and touch screen; if normal, check I2C, else U401 is abnormal. 4. Check U401. |
| Software Download Failure | 1. Check USB connector for cold solder joint. 2. Check TCXO (X801) pasting. 3. Check baseband chip MT6752 (U401) pasting. 4. Check flash U701 pasting. |
| Excessive Phase Error | 1. Check power supply part of PA and transceiver. 2. Replace elements in cold solder joint. |
| Power output problems | Check RF connector, PA, Transceiver components and their power supplies and solder joints. |
| 3G/4G forecast - RSSI_Cal | 1. Check TX module U801, U901, U902 and RF connector J1001. 2. Check U801 and surrounding circuit devices for solder joints. |
| 3G/4G forecast - TPC_Cal | 1. Check RF cable and fixtures. 2. Check RF connector J1001, Tx module U901 and surrounding circuit devices. 3. Check 3G/4G PA U901, U902. 4. Check duplexer U1001. |
| 3G/4G comprehensive test - ACLR or SEM | 1. Recalibrate WCDMA/LTE. 2. Re-weld PA or replace PA and transmission circuit devices. 3. Re-weld or replace transceiver. |
| 3G/4G comprehensive test - ILPC comprehensive test abnormal | Refer to section 4.5.1. |
| 3G/4G comprehensive test - Frequency Err | 1. Recalibrate 3G/4G and test. 2. Replace X801. |